1. Field of the Invention
This invention relates to rapid transfer port (RTP) systems for transferring articles between two environments, such as an isolator barrier chamber (the alpha flange side) and a transfer container (the beta flange side) that are adapted to be brought into close proximity to one another by a docking operation. More particularly, the present invention relates to an externally operated alpha port system that includes means for locking/unlocking and operating its door without requiring access to the internal volume of the isolator barrier chamber.
2. Description of the Related Art
Certain manufacturing processes require the maintenance of separation between two environments to avoid contamination of the cleaner of the two environments by the dirtier of the two. This is accomplished with the use of environments such as isolation barriers. For example, in the case of certain pharmaceutical products, the manufacturing process is performed within these isolation barriers to prevent contamination of the product being produced by dust particles, bacteria and viruses which are found in the outside ambient air. The same holds true for the assembly of certain medical devices. In the case of radioactive operations or bacteriological procedures, the environment within the isolation barrier is dirty as compared to the outside ambient air. In these cases, the isolation barrier serves the function of keeping the product being handled from escaping into the external environment.
In recent years, in the pharmaceutical industry, because of the expense and operational difficulties of maintaining so-called “clean rooms” into which operators enter to carry out procedures, the use of isolation barriers has become common practice. The isolation barriers, in concept large glove boxes, are integrated onto the machinery used to carry out the necessary manufacturing operations. Examples of such isolation barriers are those disclosed in U.S. Pat. No. 6,010,400 and U.S. Pat. No. 8,012,228. Variation of these isolation barriers is what is commonly known as a RABS, Restricted Access Barrier System.
Means for transferring components, product, supplies, etc. into and out of these isolation barriers without risk of contamination of the components being transferred by the “dirty” external environment during the docking and components transfer process must be provided. To accomplish this, isolator barrier chambers and RABS feature devices generally called Rapid Transfer Ports (RTP). These RTP devices may be of various type, size and configuration. A common type of RTP device is one that is offered by the French company La Calhene, referred to as the DPTE.
The DPTE port is disclosed in U.S. Pat. Nos. 3,682,208 and 3,289,698 and further disclosed to include an electrical interlocking system in U.S. Pat. No. 4,494,586 and a mechanical interlocking system in U.S. Pat. No. 5,421,626. A further variation of the DPTE type RTP port is that disclosed in U.S. Pat. No. 6,308,749 in which a lighting system provide means for sterilizing the materials being transferred into the isolator barrier chamber.
There are numerous RTP ports available other than the DPTE type RTP port. Some of these ports are disclosed in U.S. Pat. No. 5,139,318, U.S. Pat. No. 5,425,400, U.S. Pat. No. 5,460,439, U.S. Pat. No. 5,783,156, U.S. Pat. No. 5,892,200 and U.S. Pat. No. 6,779,567.
The typical RTP port is composed of two major components, the alpha port and the beta flange. Typically, the alpha flange is the half of the RTP port that is permanently mounted onto the isolator barrier chamber. The alpha port consists of the alpha flange that features the mounting means for attachment to the wall of the isolator barrier chamber and the alpha door that is hinged to the alpha flange and provides operator access into the isolator barrier chamber when opened.
The other major component of the RTP port system is the beta flange that docks to the alpha flange to gain access to the isolator barrier chamber internal volume.
A typical application of the RTP port system is to dock a beta canister such as that disclosed in U.S. Pat. No. 6,655,759 to the alpha port located on the isolator barrier chamber, reaching into the isolator barrier chamber via a glove attached to a gloveport located in close proximity to the RTP port system and then opening the alpha/beta door to complete the docking and perform the materials transfer. In some applications, the operator, also via a gloveport, positions a funnel at the outlet side of the alpha port to facilitate the transfer of the internal component into the isolator barrier chamber. One example of such transfers is that of small rubber stoppers that are used to seal off vials after aseptic filling operations internal to the isolator barrier chamber. Gloves are considered to be a primary source of contamination in isolator barrier chambers. The integrity of the gloves can be affected by small cuts and pinholes resulting from the manual operations performed. In addition, the manual operation of unlatching and opening the alpha door is somewhat undesirable from an ergonomic standpoint when performed through a glove.
Clearly then, it is desirable to provide means for latching/unlatching and opening/closing the RTP port system door without entering the isolator barrier chamber volume and a number of patents disclose various means for achieving such.
One system is that disclosed in U.S. Pat. No. 3,665,958 in which an external actuator and a spring biased closing system actuate a door of a vessel for the nuclear industry. Although not a transfer port of the RTP type, this patent shows the need for such a system in an industry other than the pharmaceutical industry. Similarly, U.S. Pat. No. 4,324,344 shows an external door closing system on a pressure vessel, not a pharmaceutical application but just the same in need of such an external actuating system.
U.S. Pat. Nos. 4,532,970, 4,534,389 and 4,616,683 demonstrate another method for actuation of the RTP port system door without entry into the isolator barrier chamber. Although the application of the above patents is for the electronics manufacturing industry, the alpha/beta port is of the RTP type that is readily used in the pharmaceutical industry. The actuation method of this invention is that of an electro-mechanical door drive system which is also seen in U.S. Pat. No. 4,724,874. U.S. Pat. No. 5,460,439 describes a system for the pharmaceutical industry that addresses both issues described above regarding the opening/closing of the RTP port system door and the positioning of a collar that is engaged during material transfer. The movement of the devices that perform the described functionality is provided by a motorized drive system that, via a control system, creates the necessary motion. This patent does not include means for locking/unlocking the door into its closed position, a necessary functionality of a manually operated system.
U.S. Pat. No. 5,139,318 discloses a transfer system that permits latching and opening of the port door without gloved access to the interior of the chamber. This patent also discloses an axially moving mechanism that separates the door from the port and a rotationally moving mechanism that moves the door away from the port opening. The patent also makes claims as to the sealing arrangement between the port door and the container lid. Although this patent addresses the issues described in the background above, it is clearly suitable for the nuclear industry but has a number of limitations in its use for the pharmaceutical industry where cleanliness and total surface exposure to decontaminating agents are key process requirements. Specifically, the axial movement of the door mechanism does not permit total surface coverage in the translating mechanism. In addition, this port system is not of the type commonly known as the alpha/beta port system. The alpha/beta port system, commonly used in the pharmaceutical industry, simply requires relative rotation of the beta flange relative to the alpha flange to complete the docking process. The port system described in U.S. Pat. No. 5,139,318 requires an additional mechanism to complete the docking, therefore adding “dirty” mechanical components on the sterile (internal) side of the isolator barrier chamber.
The invention described below addresses the issues listed in the background above in such a manner as to being compatible with the requirements of the pharmaceutical industry.